60 Starlink satellites stacked together before deployment on May 24, 2019
There are several types of satellites in space, each designed for specific purposes. Here’s a breakdown of the most common types :
1. Communication Satellites
- These are used to relay telephone, television, radio, and internet signals. They orbit in geostationary orbits, remaining fixed relative to a point on Earth.
- Examples: INTELSAT, SES Astra, HughesNet.
- Under this categories also have a Starlink, a Low Orbit Satellites, Starlink is a satellite internet constellation operated by Starlink Services, LLC, a wholly owned subsidiary of American aerospace company SpaceX, providing coverage to over 100 countries and territories. It also aims to provide global mobile broadband.
2. Weather Satellites
- These satellites monitor the Earth's atmosphere to forecast the weather, track storms, and analyze climate patterns.
- Examples: NOAA’s GOES (Geostationary Operational Environmental Satellites), Meteosat, Himawari.
3. Navigation Satellites
- Used for global positioning and navigation systems, these satellites provide GPS services for civilian and military use.
- Examples: GPS (Global Positioning System), GLONASS (Russia), Galileo (EU)**, BeiDou (China).
4. Earth Observation Satellites
- These satellites collect data about the Earth's surface for environmental monitoring, mapping, and scientific research. They are often used for studying deforestation, urban planning, and natural disasters.
- Examples: Landsat, Copernicus Sentinel, Terra.
5. Reconnaissance (Spy) Satellites
- Operated by governments, these satellites are used for military intelligence, surveillance, and reconnaissance. They collect high-resolution imagery and track troop movements or missile launches.
- Examples: KH-11, Lacrosse.
6. Astronomy Satellites
- These satellites are designed to observe distant planets, stars, and galaxies. They often carry telescopes and other scientific instruments to study space.
- Examples: Hubble Space Telescope , James Webb Space Telescope, Chandra X-ray Observatory.
7. Scientific Satellites
- These satellites are used for scientific research, including studying the Earth's magnetic field, space weather, and other planetary bodies.
- Examples: SOHO (Solar and Heliospheric Observatory), Juno (studying Jupiter), Voyager 1 & 2.
8. Space Stations
- Space stations are large manned satellites designed to support human life for extended periods while conducting experiments in microgravity.
- Examples: International Space Station (ISS), China’s Tiangong.
9. CubeSats and Small Satellites
- These are small, lightweight satellites, often used for specific scientific experiments, technology testing, or educational purposes. They are cheaper to build and launch.
- Examples: Planet’s Dove satellites, CubeSat-based missions.
10. Geostationary Satellites
- Satellites in geostationary orbit remain fixed above a point on Earth, making them ideal for communication and weather monitoring.
- Examples: GOES, INTELSAT.
Each type of satellite plays a crucial role in advancing our understanding of Earth and space, improving communication, and contributing to both civilian and military operations.
*A little bit of 'numbers' about satellites :
As of June 2024, there are more than 10,000 active satellites in orbit around Earth. The number of satellites in orbit has been increasing rapidly in recent years, with the average number increasing by almost 30% each year over the last three years.
Here are some reasons for the increase in satellites:
SpaceX
SpaceX's Starlink network is a major contributor to the increase in satellites, with over 4,000 satellites in orbit. SpaceX regularly launches more than 50 satellites at a time.
Cubesats
Cubesats are cheaper to build and launch than previous satellites, which has contributed to the increase in the number of satellites launched.
Purpose
Satellites serve many purposes, including communications, Earth and space observation, navigation, and more.
Some satellites are placed in different orbits to serve different purposes:
Geostationary orbit
This orbit is 22,236 miles above Earth's equator, and satellites in this orbit move with the same speed as Earth's rotation. Communications and weather forecasting satellites are often placed in this orbit.
Medium-Earth orbit
This orbit is located between 1,243 miles and 22,236 miles above Earth's equator. Navigation satellites such as GPS, Galileo, GLONASS, and BeiDou are often placed in this orbit.